The poetry of the universe, the periodic table, and the scientific progress: a review of new studies on the periodic table of the elements

In 1869, two distinguished scientists, Dimitri Mendeleev and Lothar Meyer, discovered a certain periodicity among the chemical characteristics of the then known elements. Both developed first versions of the periodic table, independently. In the wake of the 150th anniversary, UNESCO proclaimed 2019 the "International Year of the Periodic Table of Chemical Elements". Two lucid and detailed studies on the periodic table-accompanied by smaller studies on the occasion of the anniversary-have been published, recently, one of them analysing the scientific history, contributing to the (philosophical) theory of science (Eric Scerri), the other analysing the structures, patterns, and irregularities of the table (Geoff Rayner-Canham). Both studies are profound and vivid examples how scientific progress works. They illustrate that even in hard sciences-mirroring Merton's concept of middle range theory-the required degree of exactness can remain on an intermediate level, as imperfection allows interpretations which could not (yet) be reached by pure mathematics and logic. Both of these brilliant studies provide valuable material, especially for a social science, to better understand how scientific ideas develop, how the power of visualization helps shape ideas, and how contingency is absorbed by the scientific process.